From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Rik van Riel <riel@redhat.com>
Cc: kosaki.motohiro@jp.fujitsu.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Avi Kiviti <avi@redhat.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Mike Galbraith <efault@gmx.de>,
Chris Wright <chrisw@sous-sol.org>
Subject: Re: [RFC -v3 PATCH 2/3] sched: add yield_to function
Date: Tue, 4 Jan 2011 15:14:25 +0900 (JST) [thread overview]
Message-ID: <20110104151345.3BC2.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <20110103162918.577a9620@annuminas.surriel.com>
> From: Mike Galbraith <efault@gmx.de>
>
> Add a yield_to function to the scheduler code, allowing us to
> give enough of our timeslice to another thread to allow it to
> run and release whatever resource we need it to release.
>
> We may want to use this to provide a sys_yield_to system call
> one day.
At least I want. Ruby has GIL(giant interpreter lock). And giant lock
naturally enforce an app to implement cooperative multithreading model.
Therefore it has similar problem with your one. Python solved this issue
by slowing lock mechanism (two pthread-cond wakeup each GIL releasing),
but I don't want it.
Also, If pthread_cond_signal() call sys_yield_to imlicitly, we can
avoid almost Nehalem (and other P2P cache arch) lock unfairness
problem. (probaby creating pthread_condattr_setautoyield_np or similar
knob is good one)
next prev parent reply other threads:[~2011-01-04 6:14 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-03 21:26 [RFC -v3 PATCH 0/3] directed yield for Pause Loop Exiting Rik van Riel
2011-01-03 21:27 ` [RFC -v3 PATCH 1/3] kvm: keep track of which task is running a KVM vcpu Rik van Riel
2011-01-03 21:29 ` [RFC -v3 PATCH 2/3] sched: add yield_to function Rik van Riel
2011-01-04 1:51 ` Mike Galbraith
2011-01-04 6:14 ` KOSAKI Motohiro [this message]
2011-01-04 12:03 ` Avi Kivity
2011-01-05 2:39 ` KOSAKI Motohiro
2011-01-05 8:35 ` Avi Kivity
2011-01-05 8:40 ` KOSAKI Motohiro
2011-01-05 9:08 ` Avi Kivity
2011-01-05 9:30 ` KOSAKI Motohiro
2011-01-05 9:34 ` Avi Kivity
2011-01-05 10:24 ` Peter Zijlstra
2011-01-05 10:04 ` Peter Zijlstra
2011-01-04 17:16 ` Peter Zijlstra
2011-01-05 3:17 ` KOSAKI Motohiro
2011-01-04 14:28 ` Hillf Danton
2011-01-04 16:41 ` Hillf Danton
2011-01-04 16:44 ` Rik van Riel
2011-01-04 16:51 ` Hillf Danton
2011-01-04 16:54 ` Rik van Riel
2011-01-04 17:02 ` Hillf Danton
2011-01-04 17:08 ` Peter Zijlstra
2011-01-04 17:12 ` Hillf Danton
2011-01-04 17:22 ` Peter Zijlstra
2011-01-04 17:53 ` Rik van Riel
2011-01-04 18:05 ` Peter Zijlstra
2011-01-04 18:04 ` Peter Zijlstra
2011-01-04 18:53 ` Mike Galbraith
2011-01-05 16:57 ` Mike Galbraith
2011-01-05 17:04 ` Peter Zijlstra
2011-01-05 17:23 ` Mike Galbraith
2011-01-07 5:29 ` Mike Galbraith
2011-01-13 3:02 ` Rik van Riel
2011-01-13 3:26 ` Mike Galbraith
2011-01-13 5:08 ` Rik van Riel
2011-01-06 14:33 ` Hillf Danton
2011-01-05 17:10 ` Avi Kivity
2011-01-05 17:15 ` Peter Zijlstra
2011-01-05 17:19 ` Avi Kivity
2011-01-05 17:28 ` Peter Zijlstra
2011-01-05 17:35 ` Avi Kivity
2011-01-05 17:39 ` Peter Zijlstra
2011-01-06 3:49 ` Tejun Heo
2011-01-03 21:30 ` [RFC -v3 PATCH 3/3] Subject: kvm: use yield_to instead of sleep in kvm_vcpu_on_spin Rik van Riel
2011-01-04 6:42 ` [RFC -v3 PATCH 0/3] directed yield for Pause Loop Exiting Mike Galbraith
2011-01-04 9:09 ` Avi Kivity
2011-01-04 10:32 ` Mike Galbraith
2011-01-04 10:35 ` Avi Kivity
2011-01-04 9:14 ` Avi Kivity
2011-01-04 10:26 ` Mike Galbraith
2011-01-04 17:20 ` Peter Zijlstra
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